Your car has a strong double row chain with a short run from the cam to the crank.

On the M104 I would not say it is necessary to change the chain at 100k miles just for the fun of it. If the engine has been cared for and had regular oil changes, the chain should really last much much longer than 100k miles.

That being said, a check of the chain stretch will determine if the chain needs to be replaced. This is what you should use to determine if the chain needs a replacement if you are worried about it.

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Ali Al-Chalabi

2001 CLK55
1999 Dodge Ram 2500 Cummins Diesel
2002 Harley-Davidson Fatboy
Merlin Extralight w/ Campy Record